Gregor Hron, M.D., of the Medical University of Vienna, Austria and colleagues conducted a study to determine whether by measuring thrombin generation, patients with venous thromboembolism (VTE) could be stratified into high- and low-risk categories for recurrence of VTE. The study included 914 patients with first spontaneous VTE who were followed-up for an average of 47 months after discontinuation of vitamin K antagonist therapy. Thrombin generation was measured by a commercially available test.

“In this large prospective cohort study, we found that patients with a first spontaneous VTE and peak thrombin generation of less than 400 nM after discontinuation of vitamin K antagonists have a low risk of recurrence. According to Kaplan-Meier analysis, the likelihood of recurrent VTE in these patients was as low as seven percent after four years. Compared with patients who had higher levels, those with peak thrombin generation less than 400 nM had an almost 60 percent lower risk of recurrence. Most importantly, the group of patients with low peak thrombin generation represented two-thirds of the total patient population,” the authors write.

“We believe that our findings are of major clinical relevance. Using a simple commercially available laboratory method developed to measure thrombin generation, we were able to identify patients in whom the long-term risk of recurrent VTE is almost negligible. Considering the incidence rates of severe or fatal haemorrhage related to anticoagulant therapy and the case-fatality rate of recurrent VTE, patients with low peak thrombin generation (less than 400 nM) would almost certainly not benefit from indefinite anticoagulant therapy. Consequently, extensive thrombophilia screening appears to be unnecessary in this large, low-risk patient group,” the researchers conclude.; Source: American Medical Association (AMA)